Cannot call my child on their Apple Watch SE

Does anyone have issues calling their child on their Apple Watch SE? They do not have an iPhone and I am the Family Sharing organizer and set up the watch for them on my phone. They have their own Apple ID. All devices are up to date on system updates: My phone, their watch and also their iPad which is also connected to Family Sharing.

I manage their contacts and am in their contacts. Other numbers are able to call, which is separate from my personal phone but is also in their contacts. When I try to call from my personal phone, which is the phone that I manage family sharing from, the call goes straight to voice mail. my phone works and I am able to call other people..pls help?